Method of communicating between different electronic entities

ABSTRACT

A method of communicating between at least two electronic entities ( 121, 122, 123 ), involves a communication management unit ( 10 ) which uses a command/response protocol in order to communicate with the electronic entities ( 121, 122, 123 ). At least one of the aforementioned electronic entities ( 121, 122 ) communicates with the communication management unit ( 10 ) using wireless technology. The communication method includes a step consisting in saving a list of electronic entities in the communication management unit ( 10 ). The method can be used for microcircuit cards.

SUMMARY OF THE INVETION

The invention relates to a method of communicating between differentelectronic entities.

It applies to communication systems that use a communication protocol ofthe command-response type. In systems of this type, a communicationmanagement unit controls at least part of the process of communicationbetween a set of electronic entities by sending commands to each of theelectronic entities of this set which, after processing these commandsthey receive, which may entail complex calculations, merely respond tothose commands.

The communication management unit may be a terminal, for example, whichmay form part of the set of communicating electronic entities. This isthe case with bank cards and payment terminals used at present, forexample. The terminal executes a program for controlling the process ofcommunication between itself and the microcircuit bank card.

It is estimated that over the next two to three years there will emergea requirement for applications enabling communication between aplurality of electronic entities, in particular secure portableentities. By then robust and dynamic communication mechanisms will beneeded. For example, electronic entities may frequently and withoutwarning find themselves out of communication range. The problem of thepotential loss of messages being broadcast may then arise.

An object of the present invention is to solve this problem.

To this end, the invention proposes a method of communication between atleast two electronic entities, said method involving a communicationmanagement unit that employs a command-response protocol to communicatewith said electronic entities, this method being remarkable in that atleast one of said electronic entities communicates with thecommunication management unit using a wireless technology and in that itincludes a step consisting in storing a list of said electronic entitiesin the communication management unit.

The above method, which is particularly suitable for a command-responseprotocol, thus authorizes the intermittent presence of one or moreelectronic entities within the radius of action of the communicationmanagement unit without loss of messages being broadcast, given thatonly the messages to be sent or to be received by the electronicentities contained in the list stored in the communication managementunit will be processed. The expression “radius of action” means theregion within which communication is possible between the communicationmanagement unit and the electronic entities. One non-limiting example ofa radius of action is a radio-frequency field. By extension, the radiusof action also includes cable connections between the communicationmanagement unit and certain electronic entities.

The communication management unit is referred to as a logical processingunit (LPU) in the context of application of the invention tomicrocircuit cards using a contactless communication technology. Theinvention is particularly suited to electronic entities of this kind. Inthis application, an LPU communicates with contactless microcircuitcards within its radio-frequency field. This is because the LPU isprovided with a contactless reader whose structure is known in the artbut which is used in an unconventional way, in an environment with aplurality of microcircuits. It is used unconventionally in the sensethat it provides communication between the different electronic entitiesthat are simultaneously within the field of the LPU, in contrast to thestandard situation in which, if a plurality of microcircuits are withinthe field of the LPU, a single one of them is selected to communicatewith the LPU. The LPU may be a simple standard personal computer (PC).

The electronic entities of a set E controlled by the LPU communicatewith the latter by radio frequency using a capacitive or inductivecoupling mechanism defined in the ISO/IEC 14443, 15693 or 18000standards. The 14443 standard applies to identification cards known asproximity cards (approximately 10 cm range): “IdentificationCards—Contactless integrated circuit(s) cards—Proximity cards”. The15693 standard applies to identification cards known as vicinity cards(approximately 70 cm range): “Identification Cards—Contactlessintegrated circuit(s) cards—Vicinity cards”. The draft 18000 standardapplies to radio-frequency communication identity tags and to differentfrequencies (125 kHz, 13.56 MHz, 443 MHz, 900 MHz, etc.).

Radio-frequency applications (WiFi, BlueTooth, etc.) are not targeted bythe invention a priori. The invention could nevertheless apply to themin a command-response communication scheme using a communicationmanagement unit. The invention may equally be applied to communicationsinvolving contact, for example using a microcircuit card to the ISO 7816standard.

Generally, but not necessarily, the LPU supplies energy to thecommunicating entities.

According to one particular feature, the electronic entities constitutea network of acquaintances, i.e. a list of entities in the radius ofaction of the communication management unit and able to communicate witheach other.

This network of acquaintances has the advantage of being dynamic. Whenthe system is started up it may be either empty or preprogrammed tocontain one or more electronic entities.

According to one particular feature, the method includes a step ofadding a new electronic entity to the network of acquaintances as afunction of at least one predetermined criterion if the list of entitiesstored in the communication management unit includes that new electronicentity.

Accordingly, if a new electronic entity E enters into communication withthe communication management unit, either by connecting physically to itor by entering its radius of action, that entity E is added to thenetwork of acquaintances, and is stored therein as an acquaintance of anentity P already in the network if and only if P and E communicate witheach other subsequently. A criterion C may be used to determine thisacquaintanceship, for example the nature of the entity. The criterion Cdepends primarily on the application. The network of acquaintances maycontain only two entities, or be reduced to a simple list if all theentities in the radius of action of the communication management unitare able to communicate with each other.

According to one particular feature, the communication method of theinvention includes a step of storing a message intended for at least oneof said at least two electronic entities if the addressee electronicentity is temporarily out of range of the communication management unit.

This avoids the loss of messages if an entity temporarily leaves theradius of action of the communication management unit. As indicatedabove, the intermittent presence of an electronic entity in the radiusof action of the communication management unit is therefore possible.

According to one particular feature, a unique identifier is associatedwith each of said at least two electronic entities.

This constitutes a simple means of designating and identifying eachelectronic entity. If the electronic entities are microcircuit cards,the 7816-6/AM1 standard specifies a fabricator identifier and theconstruction of a unique identifier for each microcircuit.

According to one particular feature, each identifier is associated witha service code or application family code (as defined in the ISO 14443standard).

This enables the electronic entities to be classified according to theirnature and their application so that their designation and theiridentification may be specified.

According to one particular feature, the communication method includes astep of creating a mailbox in the communication management unit when thelist of entities that is stored therein includes a new electronicentity, this mailbox being adapted to receive and store messages sent toor sent by the new electronic entity.

Messages awaiting processing are thus saved in this mailbox.

One particular embodiment of the method includes steps in which thecommunication management unit:

-   -   scans the list of electronic entities,    -   asks each electronic entity if it has a message to send, and if        so:    -   stores this message in a mailbox,    -   sends the message to the electronic entity that is the addressee        of the message when it can be contacted, and then:    -   eliminates the message from the mailbox.

Thus the list and the mailbox enable simple and effective management ofmessages by the communication management unit.

This mailbox is an inbox, for example, i.e. it may contain messageswaiting to be sent to the associated entity.

This is the most common situation.

One particular embodiment of the communication method involves at leastthree electronic entities and combines the communication management unitwith one of the electronic entities.

The communication management unit is therefore referred to as a“participant” in that it participates in the exchange of messages withthe other electronic entities.

According to one particular feature, the communication management unitserves as a proxy, i.e. an intermediary, for accessing at least one ofthe electronic entities.

This supplementary function of the communication management unit ispractical and simple to implement.

According to one particular feature, the method includes a step ofassigning a time to live to each message awaiting reception by anaddressee electronic entity.

This enables messages whose addressee has been out of contact for a longtime to be eliminated. Depending on the requirements of the application,this time to live may be set to a special value (for example 0) toeliminate messages as soon as it is detected that their addressee is outof range of the communication management unit.

According to one particular feature, the method includes a step ofassigning a priority to each message exchanged in the context of thecommand-response protocol.

This enables the communication mechanism to process priority messagesfirst.

The communication method of the present invention is adapted tobroadcast a message from one of the at least two electronic entities toall the other electronic entities.

This enables the provision of call offering mechanisms, for example,whereby an entity requiring a particular service sends a broadcastmessage of this kind to all the known entities of the system in order toreceive one or more proposals for the provision of this service.

In one particular embodiment, at least one of the electronic entities isportable.

Thus all the practical advantages of portability are available.

In one particular embodiment, at least one of the electronic entitiescommunicates with the communication management unit using a contactlesstechnology.

This enables numerous applications. The electronic entity may dispensewith batteries and may therefore be implemented in a very compact form.

In a particular embodiment, at least one of the electronic entities issecure.

The invention therefore finds a special application to communicationbetween different secure electronic entities.

At least one of the electronic entities may be a contactlessmicrocircuit card, such as a contactless bank card, a contactless accesscontrol card, or a contactless identity card. These examples are notlimiting on the invention.

More generally, at least one of the electronic entities may be a loyaltycard or a payment card.

In one particular embodiment, the method of the invention ensurescontinuity of communication involving one of the electronic entities andan antenna from a plurality of antennas connected to the communicationmanagement unit when that electronic entity is moving in such a mannerthat the aforementioned communication involves another antenna from theplurality of antennas mentioned above.

In one special application of the present invention, the electronicentities participate in a process of personalizing a contactless objectand the process includes at least one step of mutual authentication ofthe electronic entities, reciprocal or otherwise.

This in particular enables verification that all the electronic entitiesparticipating in the personalization process are authorized to do so.

In one particular embodiment of this application, the personalizationprocess includes passing the object to be personalized in front of aplurality of stations each including wireless communication meansconnected to the communication management unit and the method ensurescontinuity of the personalization process when the object passes fromone station to the next.

In the same embodiment of the same application, the object maycommunicate with the plurality of stations using a contactlesstechnology.

This technology is particularly adapted to travel documents and officialdocuments, which increasingly, in their electronic version, use thistechnology for practical reasons. For example, a passport may retain itsoriginal format with a microcircuit inserted into the paper of thepassport using the contactless communication technology.

The present invention enables easy and robust Java Remote MethodInvocation (RMI) communication between the different electronic entitiesof the system.

BRIEF DECRIPTION OF THE DRAWINGS

Other aspects and advantages of the invention will become apparent onreading the following detailed description of particular embodiments ofthe invention, which are provided by way of nonlimiting example. Thedescription is given with reference to the accompanying drawings, inwhich:

-   -   FIG. 1 is a diagram of a communication management unit and        different electronic entities using the present invention;    -   FIG. 2 is a flowchart of the main steps executed upon the        implementation of one particular embodiment of the communication        method of the present invention;    -   FIG. 3 is a flowchart of the main steps executed upon the        arrival of a new electronic entity in the radius of action of        one particular embodiment of the communication management unit        of the invention; and    -   FIG. 4 is a diagram of one particular embodiment of a device of        the present invention for personalizing objects.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown in FIG. 1, one particular embodiment of the communicationmethod of the present invention uses a logical processing unit (LPU) 10that functions as a communication management unit using acommand-response communication protocol and therefore controls at leastpart of the process of communication between a plurality of electronicentities 12 ₁, 12 ₂, 12 ₃.

Here the electronic entities 12 ₁ and 12 ₂ are microcircuit cards eachprovided with an antenna and communicating with the LPU 10 using acontactless technology and the electronic entity 12 ₃ is a securehardware module (SHM) and communicates with the LPU 10 via a cableconnection. However, more generally, the electronic entities 12 ₁ and 12₂ may communicate with the LPU 10 using a wireless technology conformingto the BlueTooth, WiFi, etc. standards. The radius of action of the LPU10 is represented in dashed lines in the drawing and here corresponds tothe region subjected to a radio-frequency field.

The communication method of the present invention includes a step ofstoring in the LPU 10 a list of the electronic entities that are able tocommunicate with it (labeled “list” in the drawing).

The electronic entities 12 ₁, 12 ₂ and 12 ₃ form a network ofacquaintances, i.e. they are able to exchange messages.

As described in the introduction, this network of acquaintances isdynamic in the sense that it evolves as a function of the arrival of oneor more new electronic entities in the radius of action of the LPU 10or, conversely, upon the departure of one or more electronic entitiesfrom that radius of action.

Accordingly, when the electronic entity 12 ₄, which here is acontactless microcircuit card (but could equally well communicate withthe LPU using a wireless technology conforming to the BlueTooth, WiFi,etc. standards), enters into communication with the LPU 10, on arrivingin its radio-frequency field, not only is that entity added to the liststored in the LPU 10 but also the new entity 12 ₄ is registered as anacquaintance of the entity 12 ₁ if and only if both these entitiescommunicate with each other subsequently and, similarly, the new entity12 ₄ is registered as an acquaintance of the entity 12 ₂ if and only ifthese two entities communicate with each other subsequently and the newentity 12 ₄ is registered as an acquaintance of the entity 12 ₃ if andonly if these two entities communicate with each other subsequently. Fordetermining these acquaintances, a criterion C may be used such as twoentities of the same type being able to communicate with each other, forexample.

Moreover, for each of the entities 12 ₁, 12 ₂ and 12 ₃ in the system theLPU 10 manages a mailbox that stores messages awaiting processing. Forexample, if the electronic entity 12 ₂ temporarily leaves theradio-frequency field and the LPU 10 then receives a message for theentity 12 ₂, that message is stored in the mailbox assigned to theentity 12 ₂ until the entity 12 ₂ returns to the radio-frequency field.Similarly, if the entity 12 ₃ disconnects temporarily from the LPU 10and the LPU 10 then receives a message for the entity 12 ₃, that messageis stored in the mailbox assigned to the entity 12 ₃ until the entity 12₃ reconnects to the LPU 10.

When the new entity 12 ₄ enters the network, a mailbox is created in theLPU for that entity and contains messages awaiting processing by the newentity 12 ₄.

An electronic entity is eliminated from the network if it leaves theradio-frequency field or is physically disconnected from the LPU 10, andif its mailbox is empty and none of its acquaintances has a message forit.

Each electronic entity is identified by a unique identifier. Typicallythe identifier described in Part 3 of the ISO 14443 standard or in theISO 7816-6/AM1 standard is chosen. This identifier is advantageouslyassociated with a service or family code describing the optionssupported by the entity and forming part of the criterion C ofacquaintanceship between entities.

Accordingly, if the entity 12 ₁ wishes to send a message to the entity12 ₂, it can do so by indicating the identifier of the entity 12 ₂ or byspecifying only the service or family code of the entity 12 ₂. In thiscase, the LPU 10 always chooses the same addressee for the same serviceor family code from one message to another. Alternatively, and dependingon the nature of the application, any deterministic or non-deterministicmethod may be used to choose the addressee of a message by means of itsservice or family code.

The FIG. 2 flowchart shows the main steps executed by the LPU 10 onimplementing a communication process conforming to the invention.

The LPU 10 scans the list of electronic entities. For each entity E ofthe network (step E80), the LPU 10 tests whether the mailbox B assignedto the entity E is empty (test E82) . If the mailbox B is empty, the LPU10 sends an interrogation message to the entity E (step E84). The LPU 10then tests whether the entity E sends back an acknowledgement (test E86). If the entity E sends back an acknowledgement, the LPU 10 effects thesame exchange with the next electronic entity (steps E82, E84, E86).

If not, i.e. if the entity E does not send back an acknowledgement, theLPU 10 tests whether the entity E responds that it has a message M tosend to an entity D (test E88). If the entity E has a message M for theentity D, the LPU 10 places the message M in the mailbox of the entityD, whereupon the process resumes for the next electronic entity,starting from the test E82.

If, during the test E88, the entity E no longer responds, the LPU 10eliminates the entity E from the network, after which the processresumes for the next electronic entity, starting from the test E82.

If, during the test E82, the mailbox B of the entity E is not empty, theLPU 10 sends the entity E the oldest message M from the mailbox B (stepE94) . The LPU 10 then tests if the entity E sends back anacknowledgement of the message M (test E96) . If not, the processresumes for the next electronic entity, starting from the test E82.Otherwise, i.e. if the entity E acknowledges receiving the message M,the LPU 10 eliminates the message M from the mailbox B (step E98). Inthe most usual situation, B is an inbox, but B could instead be anoutbox.

The FIG. 3 flowchart summarizes the mechanism following the arrival(step E30) of a new electronic entity in the radius of action of the LPU10. The LPU 10 creates a mailbox B for the entity E (step E32) and thentests whether the criterion C determining the addition of the entity Eto the network of acquaintances is satisfied (test E34). If this is thecase, the LPU 10 adds the entity E to the network of acquaintances (stepE36) and, for each entity already present in the network, registers theentity E as an acquaintance of that entity if and only if the twoentities communicate with each other subsequently.

The network of acquaintances may be implemented in different ways. Forexample, it may take the form of a table of dynamic acquaintances in thememory of the LPU 10, i.e. a table of correspondences associating eachelectronic entity with its acquaintances. The network of acquaintancesmay instead be divided between the memories of each of the electronicentities, each of which then knows its own acquaintances.

Diverse variants of and improvements to the embodiment described abovemay be envisaged.

The LPU may be seen as an electronic entity always connected to thesystem. It then has its own identifier, service or family code andmailbox for receiving messages from other electronic entities, and isreferred to as a “participating LPU”.

One of the electronic entities may be accessible indirectly through anyopen network via a rerouting or proxy system. The LPU may then serve asa proxy for that remote entity.

A time to live (TTL) may be specified for a message awaiting itsaddressee. This eliminates messages that have become obsolete becausetheir addressee disappeared a long time ago. In certain applications,the parameter TTL may also be set to a special value (for example thevalue 0) to cancel a message as soon as it is detected that itsaddressee is out of range of the LPU.

The messages may be assigned a priority P. In this case, thecommunication mechanism handles the highest priority messages first.

Depending on the intended application, it may be advantageous to use acall offering mechanism: an entity that requires a particular servicesends a broadcast message to all the known electronic entities of thesystem, i.e. to all of the items in the list stored in the LPU. Theinterested entity or entities can send a proposal to provide the servicethat the requesting entity can accept or refuse according to its owncriteria.

The whole of the call offering mechanism (the broadcast message, theresponses and then the acceptance message from the requesting entity)uses the communication method of the invention. At the end of the calloffer, the LPU may complete its table of dynamic acquaintances, forexample by indicating whether a particular entity knows how to providethis kind of service.

A TTL parameter may be associated with the broadcast message.

If a new entity enters the radius of action of the LPU, a particularbroadcast message is broadcast to all the entities already present inthe network and indicates in particular the identity of the incomer andits service or family code. This mechanism is known as the “broadcast onincoming” mechanism.

In a similar manner, if an electronic entity leaves the radius of actionof the LPU, a particular broadcast message is broadcast to all theentities still present in the network. This message indicates inparticular the identifier of the departing entity and its service orfamily code and this mechanism is known as the “broadcast on outgoing”mechanism.

If a plurality of electronic entities participate in a distributedcalculation, it is possible to regard the sending of a message Ml froman entity El to an entity E2 as a calculation request. An explicitcalculation continuation entity E3 may be specified in the message.Accordingly, when the entity E2 has finished the calculation effected onreception of the elements of the message Ml, it sends a calculationcontinuation request by sending a message M2 to the entity E3.

Different examples of the use of the invention are given next.

First of all, in the field of air passenger loyalty, consider apassenger who has a loyalty card for airline X. The passenger purchasesa transport ticket from the company X and goes to the VIP lounge toawait boarding.

A hostess carries a new generation location terminal capable of usingthe mechanism of the present invention. She holds a hostess card with aclientele management application.

When the passenger passes near the terminal of the hostess, his loyaltycard and ticket declare themselves to the terminal. After appropriateauthentication, the hostess card asks the transport ticket for theidentity of the passenger and asks the loyalty card for the number ofloyalty points associated with that passenger.

If the hostess card detects a loyal customer (having a number of loyaltypoints exceeding a particular threshold), the hostess offers thepassenger his preferred drink, for example, this information beingstored in the loyalty card. The hostess card then transfers to theloyalty card a voucher valid in one of the shops of the departurelounge, for example.

By way of a second example, consider a customer having in his wallet abank card and a loyalty card. In addition to their standard mode ofoperation, the two cards know how to communicate securely via acontactless interface.

Consider also a merchant having a new generation payment terminalcapable of using the mechanism of the present invention.

The customer makes a payment with his bank card by entering his PIN inthe usual way, but without having to take his bank card out of hiswallet. Once the payment has been validated, the bank card sends abroadcast message to search for a loyalty service for the store in whichthe purchase has just been effected. The loyalty card proposes itsservices by specifying that it accepts the task of storing loyaltypoints in accordance with the request from the bank card.

The bank card then transmits to the loyalty card the number of loyaltypoints to be credited to the account of the customer, and the loyaltycard credits those points.

If the wallet of this customer contains another loyalty card, such asthe card of a transport operator, this other card may also ask the bankcard the nature of the purchase before proposing its services. The threeelectronic entities then communicate.

In order to secure the exchanges between these different entities, afourth electronic entity (SHM type secure electronic entity) may beinserted into the body of the payment terminal and participate incertain authentication operations on behalf of the other threeelectronic entities.

An example of the application of the invention to personalizing objectsis described next. The term “personalization” means the writing ofpersonal data specific to an object in or on the object by mechanical,electronic, optical, chemical or any other means.

Consider a personalization machine comprising a plurality of stations.The object to be personalized is placed for a particular time in frontof each station and then moved to the next station. Because the timingof the movement from one station to another is not strictly defined,some messages may be lost during the movement from one station to thenext.

FIG. 4 shows a device of this kind. An LPU 40 is connected to a securityhardware module SHM 42 and to three antennas al, a2, a3 each designatedby the reference number 46. Each of the antennas 46 corresponds to aworkstation of a machine for personalizing objects 44 that move fromstation to station. The SHM 42 contains the necessary personalizationinformation. The arrow 48 in the diagram delimits a “shadow area”, whichis an area of radio-frequency interference through which the object tobe personalized passes between two successive workstations.

Here the invention applies advantageously to the electronic entitiesconsisting of the SHM 42 and the object 44 to be personalized. Thus theobject disappears from the list of dynamic acquaintances when it entersthe area 48 and then reappears in the list when it is in front of a newworkstation.

When the object is in the area 48, current messages are saved inmailboxes according to the invention, as described above. There istherefore continuity of communication between the object 44 and the SHM42 via the LPU 40 and the different antennas 46.

More generally, the method of the invention provides continuity ofcommunication involving an electronic entity and an antenna from aplurality of antennas connected to a communication management unit ifthis electronic entity moves in such a manner that the communicationinvolves another antenna from the abovementioned plurality of antennas.

Finally, the present invention may advantageously be used for the securepersonalization of an object including a first secure set consisting ofa first storage unit and a first microcircuit by a personalizationmethod that employs n−1 secure sets in addition to the first secure set,n being an integer strictly greater than 2, each of the secure setsconsisting of a storage unit and a microcircuit and forming with theobject an authorized n-tuplet known to at least one of the secure sets,and the personalization method including a plurality of mutualauthentication steps of pairs of secure sets, prior to a personalizationstep consisting in writing personal data specific to this object on orin this object.

One or more of the microcircuits previously cited may be adapted tocommunicate with the external environment using a contactlesstechnology.

The object to be personalized is a document issued by the state, forexample, such as an identity card, a passport, a visa, a vehicleregistration document, or any other document of an official nature, suchas a notarized document, a transport ticket such as a season ticket foruse of public transport, or a travel document, such as a driver'slicense or a toll ticket or other proof of a right of transit, forexample of the type issued by the authorities of Mexico City so thatmotorists may enter the city.

The n−1 secure sets mentioned above may be taken from:

-   -   a secure set representing a batch of objects to be personalized,    -   a secure set including a secure electronic entity associated        with a machine adapted to personalize the objects of this batch,        and    -   a secure set attached to an operator authorized to use the        machine.

This enables secure personalization of any object forming part of abatch, such as an identity card taken from an initial batch of cards tobe personalized, personalization being effected by means of an approvedmachine identified by an associated machine secure module, operated byan approved operator identified by an operator microcircuit card in hispossession, for example, which identifies him uniquely.

For more details of this personalization method, see French patentapplication No. 02 15551.

The invention claimed is:
 1. A method of communicating between at leasttwo electronic entities having contactless communication means, saidmethod comprising: using a communication management unit to control atleast part of a process of communication between said electronicentities, said communication management unit (LPU) employing acommand-response protocol using said contactless communication means tocommunicate with said electronic entities upon said electronic entitiesbeing within a radius of action of said communication management unit;storing in said communication management unit a list of said electronicentities that are within the radius of action of said communicationmanagement unit; and querying each of the electronic entities todetermine if any of the electronic entities has a message to be sent toan other of said electronic entities; and for each electronic entity ofsaid list, sending an interrogation message from said communicationmanagement unit to the electronic entity, in order to determine if theelectronic entity has a message to be sent to another of said electronicentities, a determination being positive upon receiving, in response tothe interrogation message, said message to be sent to said otherelectronic entity, otherwise said determination being negative, where,in the case of a positive determination, storing a received message in amailbox of said communication management unit that is assigned to saidelectronic entity or to said other electronic entity, and where in thecase of a negative determination, if no acknowledgment from theelectronic entity is received in response to the interrogation messagethereby showing that the electronic entity is no longer within saidradius of action, removing the electronic entity from said list ofelectronic entities, wherein, when said list includes a new electronicentity, a mailbox is created in the communication management unit, saidmailbox being adapted to receive and store messages sent to or by saidnew electronic entity.
 2. The method according to claim 1, wherein saidelectronic entities constitute a network of acquaintances.
 3. The methodaccording to claim 2, wherein, upon said list including a new electronicentity, the method further comprising a step of adding the newelectronic entity to said network of acquaintances as a function of atleast one predetermined criterion.
 4. The method according to claim 1,wherein each of said electronic entities is associated with a uniqueidentifier.
 5. The method according to claim 4, wherein each identifieris associated with a service or family code.
 6. The method according toclaim 1, wherein at least one of said electronic entities is secure. 7.The method according to claim 1, wherein at least one of said electronicentities is a loyalty card.
 8. The method according to claim 1, whereinat least one of said electronic entities is a payment card.
 9. Themethod according to claim 1, wherein the method ensures continuity ofcommunication involving one of said electronic entities and an antennafrom a plurality of antennas connected to the communication managementmeans when said electronic entity moves in such a manner that saidcommunication involves another antenna from said plurality of antennas.10. The method according to claim 1, wherein said list of saidelectronic entities includes a list of all of said electronic entitiesseparate from a list of said electronic entities in communication withother said electronic entities.
 11. The method according to claim 1,wherein one of the electronic entities is a proximity card with a 10 cmrange and that complies with ISO/IEC standard 14443, and an other one ofthe electronic entities is a vicinity card with a 70 cm range and thatcomplies with ISO/IEC standard
 15693. 12. The method according to claim1, wherein at least one of said electronic entities is a contactlessmicrocircuit card.
 13. The method according to claim 1, wherein saidelectronic entities include said other of the electronic entities and asender entity, and wherein said message is sent from the sender entity.14. The method according to claim 1, further comprising: upon contactingsaid other of the electronic entities intended to receive the message,sending the message to said other of the electronic entities.
 15. Acommunication system, comprising: at least two electronic entitieshaving contactless communication; and further comprising: employing acommand-response protocol to communicate with said electronic entitiesusing said contactless communication upon said electronic entities beingwithin a radius of action of said communication management unit, saidcommunication management unit having stored therein a list of saidelectronic entities that are within the radius of action of acommunication management unit, wherein at least one of said electronicentities communicates with said communication management unit using saidcontactless communication, wherein said communication management unit isconfigured to, for each electronic entity of said list, send aninterrogation message to the electronic entity in order to determine ifthe electronic entity has a message to be sent to another of saidelectronic entities, a determination being positive upon receiving, inresponse to the interrogation message, said message to be sent to saidother electronic entity, otherwise said determination being negative,where, in the case of a positive determination, the communicationmanagement unit stores a received message in a mailbox of saidcommunication management unit that is assigned to said electronic entityor to said other electronic entity, and where in the case of a negativedetermination, if no acknowledgment from the electronic entity isreceived in response to the interrogation message thereby showing thatthe electronic entity is no longer within said radius of action, thecommunication management unit removes the electronic entity from saidlist of electronic entities, and when said list includes a newelectronic entity that is configured to exchange messages with at leastone of the electronic entities, creating a new mailbox, said new mailboxconfigured to receive and store messages sent to or by said newelectronic entity.
 16. The communication system according to claim 15,wherein one of the electronic entities is a proximity card with a 10 cmrange and that complies with ISO/IEC standard 14443, and an other one ofthe electronic entities is a vicinity card with a 70 cm range and thatcomplies with ISO/IEC standard
 15693. 17. The communication systemaccording to claim 15, wherein said communication management unitfurther includes means for sending the message to said addressee entityupon a determination that said addressee entity can be contacted.